Glutamate & Glutamine-Article

[Zoe]

The quote and link below is to a study that was published in the Food and Nutrition Bulletin in 1985. Note that the concern of neurotoxicity is with the free glutamate found in MSG, not the bound glutamate found in most natural foods. The article is very informative. In it's bound form, glutamate is attached to 20 other amino acids and breaks down differently, more slowly and is less likely to be a problem. That may be contingent on how it is prepared in cooking. Tomatoes and some other foods do contain free glutamate as in MSG, and can be toxic.

"Glutamate has been recognized to be both neuroexcitory and neurotoxic. Biological actions of ODAP and glutamate (MSG) have been correlated (15). It occurred to us that the toxic effect of MSG reported in young animals could possibly be counteracted by AA. As described below, it has been our finding that AA does protect young animals from the neurological symptoms that arise from administration of a high dose of MSG. AA can both prevent and cure the toxic effects of MSG. Therefore, the incorporation of AA with MSG in food preparations might possibly preclude toxic reactions to MSG in human subjects. "
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This next paragraph is from the same article. I wonder if it is people who are low in vitamin C who are most likely to have a toxic reaction to the glutamate in MSG-if not food as well? Something for us all to ponder.

Experiments with Guinea-pigs and Monkeys

"These studies were made to demonstrate the curative action of AA against MSG toxicity in adult guinea-pigs and monkeys, which are not able to biosynthesize AA. Guinea-pigs weighing 300-350 9 and monkeys weighing 2.5-3 kg were selected. They were made deficient in AA by feeding an AA-deficient diet until serum AA levels fell to 0.3-0.4 mg/dl. At this point no scorbutic symptoms were seen. A dose of 2 g/kg of MSG was administered to each animal intraperitoneally in a 0.5-ml aqueous solution. Results are shown in table 2, parts B and C. All the animals became sick, but 5 mg of AA given subcutaneously cured all of the guinea-pigs, and 50 mg cured all monkeys. These doses were arbitrary."


http://nzdl.sadl.uleth.ca/cgi-bin/li...e1a43d803c.3.1